


Damn Gwaine

by cominupforair



Category: Merlin (TV)
Genre: Alternate Universe - Modern Setting, Anal Sex, Boys In Love, Kink Meme, M/M, Plot What Plot/Porn Without Plot, Porn with Feelings, Secret Relationship
Language: English
Status: Completed
Published: 2018-08-26
Updated: 2018-08-26
Packaged: 2019-07-02 18:07:09
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,665
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15801837
Author URL: https://archiveofourown.org/users/cominupforair/pseuds/cominupforair
Summary: The truth is that Arthur didn’t know when Merlin had stopped being just his best mate’s little brother and had become something more. The only thing Arthur knew was that now he couldn’t keep his hands to himself.(This is a fill for this Kink Meme prompt: "Merlin and Arthur have been dating/fucking for a while but they haven’t told anybody. Especially because they fear Gwaine’s reaction cause Gwaine is Merlin’s brother and Arthur’s best friend and he would not take it well.")





	Damn Gwaine

**Author's Note:**

> For the purposes of this fic, Gwaine is deliberately pictured as the thickest guy who ever walked the Earth. I'm sorry Gwaine, you're better than this, I know, I love you. 
> 
> Completely unbetaed, all mistakes are mine, I'm sorry!

The truth is that Arthur didn’t know when Merlin had stopped being just his best mate’s little brother and had become something more. The only thing Arthur knew was that now he couldn’t keep his hands to himself. 

“I think we should tell them,” Merlin said as he gripped the edge of the table, hopelessly trying to keep himself from slipping from the desk. His legs on Arthur’s shoulders and Arthur’s fingers pumping rhythmically in his ass.

“W-what?” Arthur panted in his ear. 

“I think we should tell our friends of-“ Merlin tried to explain himself but Arthur chose that moment to slip another finger in his ass without notice. Merlin whimpered. “Jesus Christ, you’re a fucking bastard,” he mumbled breathlessly. Arthur grinned, sweetly peppering Merlin’s flushed cheeks with light kisses to apologise for the unexpected intrusion. 

“Sorry Merls, what were you saying?” Arthur kept his lips pressed against Merlin’s temple as he sped up his pace, lightly grazing that sweet little spot that made him come undone and erasing every trace of discomfort from his boyfriend’s face. 

“Ithinkweshouldtellourfriends,” Merlin blurted out, almost unintelligibly, as Arthur kept pressing on his prostate and sending jolts of pleasure through his body. At that point Merlin was panting frantically but he tried to repeat again, “I think we should tell our friends of THIS,” and if he finished that sentence squealing, well it was totally Arthur’s fault who was doing wicked things with his fingers. 

“Yes, that would go down well. I can’t wait to tell my best mate Gwaine that I deflowered his little brother”

Merlin was squirming in anticipation, using his legs as leverage to fuck himself deeper on Arthur’s fingers. “I swear Arthur, if you don’t put your cock in my arse right in this fucking moment I’m going to tell Gwaine myself and root for him as he beats you up”. 

“You really are a sweet-talker, aren’t you?” 

“Don’t act surprised, you’ve known me since I could barely walk, now get on with it,” Merlin demanded impatiently as he tried to grind down again. But Arthur chose that moment to remove his fingers from Merlin’s ass, leaving him empty and open, lube dripping from his hole onto the papers scattered on the desk. He poured another dollop of lube in his hands and coated his erection.

“Maybe Gwaine’d stop calling me ‘princess’ if he found out that fucking you on his desk is my new favourite pastime” Arthur rebutted. With that, he leaned his forehead against Merlin’s as he guided the tip of his cock towards Merlin’s entrance and pushed slowly all the way up his arse, feeling it stretch around him. Christ, it was so tight, so tight he had to wrap his fingers around the base of his cock and squeeze a bit to keep himself from coming just from that.

Inhale. Exhale. Inhale. Exhale.

Breathing into Merlin’s shivering mouth, Arthur managed to get a grip before he gave one last push, letting his cock be entirely engulfed by that sweet hot hell. 

He looked into Merlin’s eyes checking for any sign of discomfort. “You okay?”, he said softly, releasing a puff of breath against his boyfriend's ear. 

A nod and then a breathless “Yeah”

“Can I move?” he asked, hesitant, not wanting to hurt him. 

In response Merlin leaned slightly backwards, shifting his weight and producing the exact amount of friction to make Arthur gape and let go of his last restraints. He snapped his hips, once, and then twice, till his balls were slamming against Merlin’s arse and making obscene squelching sounds. 

Merlin’s legs were trembling from the strain of keeping them on Arthur’s shoulders, but he still tried to accompany every movement and fuck himself on his cock, setting a frantic pace for himself. Arthur groaned and tried to go faster as he felt the beginning his orgasm building, just, just-

A knock on the door. “Merls?”

Shit. Shitshitshit. Gwaine. Arthur stopped moving and looked at Merlin like a frightened rabbit, seeing the same expression of terror reflected in his eyes. 

Merlin cleared his throat. “What do you want Gwaine?” 

“I’m was at Percy’s to do the algebra project for next week, but I’ve forgotten my notes on my desk”

It took Arthur one second to realise that Merlin was looking at the sheets of paper spread under himself with an horrified expression. 

Fuck. 

“Merlin did you hear me?”

“Yes, yes, just a sec Gwaine!”. And as he said so the horrified look give way to a mischievous grin. Arthur didn’t even have the time to realise what was going on before Merlin tightened his legs’ grip on Arthur’s shoulders and resumed rolling his hips.

Arthur stared at him wide-eyed. He- He couldn’t possibly. “What do you think you’re doing?” he whispered frantically while Merlin began fucking himself on his cock. “Gwaine’s out there!”

“Yes, I know, and you better make me come quickly before he bangs the door open and finds his best friend buggering his adored little brother”

Arthur was still staring at him with his mouth open. Merlin had gone completely nuts if he thought that he would keep fucking him when Gwaine was behind the door. No way. He was about to protest again before his brain caught up with the fact that his cock was still interested, thank you very much.

He glanced at Merlin’s defiant smirk and oh, fuck it, he started moving again in quick, deep thrusts. The skin of Merlin’s thighs was turning white under Arthur’s strong grip as he kept pounding and pounding, as desperate as he’d never been before. He distractedly registered the fact that Gwaine was probably still speaking on the other side of the door, but he couldn’t understand shit.

He. Just. Wanted. To. Come.

He leaned his head forward finding Merlin’s mouth and, on an impetus, he bit on Merlin’s lower lip to keep himself from shouting because of the impossible mixture of white hot lust and frustration. 

The room was completely silent, except for the filthy squelching sound of lube and the slap of skin against skin that grew louder with every thrust. Arthur was so focussed on coming in Merlin’s ass as soon as he could that he failed to realise that now that he had Merlin’s bottom lip between his teeth, Merlin’s mouth was left open.

And he really shouldn’t have been surprised when that bastard clenched around him and moaned spectacularly before he spurted come all over his stomach. 

He. Was. Fucked. There was no way Gwaine hadn't heard that moan. Hell, probably even Hunith had heard it from the backyard. 

Merlin let go of his grip of the desk and collapsed on top it, letting Arthur do whatever he wished with his spent body.  And Arthur who was already on the edge bit Merlin’s inner thigh to keep himself from shouting and kept pushing. He was just one step away from coming, just one more thrust when- 

“Merlin what the fuck are you doing? I’m going to bang this door open if you don’t unlock it right. fucking. now” The door was rattling under Gwaine’s pushes. 

At that Merlin perked up immediately, whispering frantically “out out out” as he tried to get down the desk even when he was still impaled on Arthur’s cock. 

Arthur got out from his arse with a groan, his cock still hard, angry red and neglected, instantly missing the warmth and mentally cursing both Gwaine’s timing and Merlin’s insolence.

Merlin started collecting their clothes from the floor and throwing them at him. Arthur caught his jeans with his left hand and tried to will down his erection because no, thanks, he didn’t want Little Arthur to get stuck in the zip and getting dressed when his cock still thought he had a chance of release was no easy thing. 

He was still buttoning up his shirt when Merlin, feigning innocence but with his hair still rumpled by Arthur’s fingers, turned to unlock the door just one second before Gwaine unhinged it, at least judging from the noise he was making. 

“Merlin what the fuck?”. Gwaine barged into the room red-faced and shouting. 

Merlin had the decency to look a little sheepish before he blurted “Sorry we were a little busy here” pointing at Arthur with his thumb.

Gwaine’s eyes widened as he took in everything. Arthur’s crumpled shirt, Merlin’s blotched cheeks and puffed mouth (still sporting an evident bite on his bottom lip), not to mention that the room evidently reeked of sex. It wasn’t difficult to put two and two together, even someone as thick as Gwaine could do it. 

A beat. “And what exactly were you busy doing?”

“Fucking” answered Merlin with nonchalance and a shrug.

Arthur froze.

He didn’t think that Gwaine’s eyes could get any wider, but they did. Shifting his gaze from his boyfriend’s proud expression and his best mate’s gobsmacked face, Arthur felt sheer panic welling up in his stomach.

Gwaine turned to stare at him. He was seeing red, that much was clear from the vein bulging on his forehead. And Arthur opened his mouth, willing his mind to think of something he could tell Gwaine, an excuse, an apology, just something. But he was at loss, so he just stared at him with his mouth agape like a fish.

Brilliant Arthur, really. 

He was 100% sure that Gwaine was about to smack his head against the nearest pointed surface and break his nose when Merlin started laughing. At first it was just a light giggle but then it turned into a loud laugh that made him throw his head backwards. 

Both Arthur and Gwaine turned to stare at him, but Merlin kept laughing. “I- I was joking Gwaine,” he wiped a tear from his eye, trying to recompose himself, “Arthur was just giving me a hand with my maths assignment, you know he’s a wizard with that kind of thing”.

Gwaine didn’t look convinced. It didn’t explain why the door was locked after all. “And why exactly was he here? Did you call him?”

“No, he was actually looking for you,” Merlin replied, pointing his index on Gwaine’s chest, “cause you’d told him that you and Percy needed his help with algebra. That’s why he came over, but then I stopped him on his track and begged him to give a look at my homework. He’s all yours now”

Arthur had clearly overestimated Gwaine’s acumen when faced with such an offer because his murderous stare quickly morphed into a puppy-like smile. Bless him. He was just like a child, really, could not process two things at the same time.

“Seriously mate?”

Saying that Arthur was slightly confused by the quick turn of the events would be an understatement. He was still trying to wrap his head around the fact that he’d passed from buggering Merlin to being about to be skinned alive by Gwaine in a matter of minutes. Still uncomprehending, he mumbled a “yeah” and before he could even realise the implications of what he’d agreed to (an entire afternoon explaining maths to Gwaine _and_ Percy!), he found himself enveloped in Gwaine’s arms.

“You’re the best, I knew I kept you around for something!”

“You mean apart from being the only human being who puts up with you on an almost daily basis?!”

At that Merlin interrupted with a “Not to break it to you, but I deserve that title, I’ve been putting up with him since the day I was born, _literally_. Now could you two please just get out of my room?” 

Gwaine rolled his eyes, “first of all, this is _our_ room,” he tilted his head towards his bed. “Not yours. Then, don’t get your knickers in a twist Merls, I just need to pick up my notes.”

At that Arthur froze once again.

 

The notes. The notes on the desk. The notes smeared with the lube that had dripped from Merlin’s arse while he was being fucked, on the desk. 

“I’ll get them for you while I gather my things,” Arthur said nonchalantly, “you go downstairs, call Percy and tell him that I’m going to help you both on one condition,” he raised one finger to his mate’s worried face, “there has to be at least one beer can waiting for me in his fridge”. 

Gwaine answered with a blinding smile, a pat on his back and an enthusiastic “Of course mate!”. 

As soon as Gwaine walked out of the room, Arthur breathed a sigh of relief. He hadn't put two and two together but then again maths wasn’t Gwaine’s forte. Ignoring Merlin, he bent on the desk and started gathering all the scattered papers, trying to hide the lube-coated ones at the end of the pile. They’d been so fucking caught up in the moment that they’d made a fucking mess out of the room. 

For a moment, the shame he felt was quickly washed over by the memory of Merlin’s lustful moan. (How the fuck did Gwaine not hear it?) And at that, Arthur’s cock twitched a bit in his pants. Still hard and full and angry. 

Arthur slammed his hands on the desk in a fit of anger. “See? That’s why we can’t tell Gwaine,” he mumbled, giving his back to Merlin and refusing to meet his eyes. The fact that he could not tell Gwaine was hurting him more than he dared to admit. He was still his best friend. Arthur wasn’t meant to fuck Gwaine’s little brother. He wasn’t meant to, oh god, he wasn’t meant to fall for Merlin. It was all part of the unwritten code of friendship. You don’t fuck with your friends’ family and exes. Full stop. 

His mental breakdown was interrupted by Merlin gently hugging him from behind and splaying his daft fingers on his ribs. He softly kissed the back of Arthur's neck before he rested his head on his shoulders. “It’s quite the opposite,” Merlin said in his ear. 

Arthur felt Merlin’s hands wandering on his torso, his pecs, the lightly defined abs and lower, lower. Merlin could probably feel his breath quickening under his palms. “You should tell him,” Merlin whispered on his neck. 

“A-Are you nuts?” Arthur asked with a noticeable hitch in his voice. 

Merlin finally let his hands go south and rest on Arthur’s hard on, still painfully constricted in his jeans. He gripped the outline of his cock possessively and said “You should tell him because, if he knew, now I could get on my knees and suck you off,” Merlin’s words went straight to his groin and Arthur shivered. As if he wasn’t already hard enough! But Merlin continued, “I’d let you come on my face and then I’d lick your spunk off my lips” 

At that Arthur let a broken moan escape his lips. He tried to get a hold of Merlin’s wrist, just to make him press his hand harder on his cock, looking for some kind of friction. But Merlin swiftly escaped his grip and put some distance between them. 

Arthur turned around and tried to get back in his space, but Merlin ignored his effort and continued, “unfortunately Gwaine doesn’t know, so now you have to go help him with his algebra assignments because you promised him and you have no excuse to stay here since I’m not your boyfriend, I’m just your best mate’s little brother.” Merlin was smiling smugly, satisfied with his witty comeback and if Arthur weren’t so damn in love with that stupid mug he would’ve probably punched him in the face in that moment. 

“That’s why you should tell him”, Merlin concluded, “for the sake of your cock if nothing else.” 

Merlin quickly glanced at his groin as if to prove his point and then walked out of the room, leaving Arthur with a raging hard on, a bunch of lube-smeared notes in his hands and an entire afternoon of putting up with Gwaine.

Damn Gwaine. 


End file.
